Ozonizer

ABSTRACT

An ozonizer has a flat plate-shaped low voltage electrode and a flat plate-shaped high voltage electrode facing a main surface of the low voltage electrode. The ozonizer also has a flat plate-shaped dielectric and a spacer for forming a discharge gap having a thickness in a laminating direction, provided between the low voltage electrode and the electrode, an electrode cooling sheet facing a main surface of the electrode at a side opposite the discharge gap for cooling the electrode. The ozonizer also has a thermally conducting and electrically insulating sheet sandwiched between the electrode and the electrode cooling sheet. An alternating voltage is applied between the low voltage electrode and the electrode and a discharge is produced in the discharge gap so that, when filled with oxygen, ozone gas is produced.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a flat plate laminate ozone generating apparatus including a plurality of laminated plate-shaped high voltage electrodes and low voltage electrodes between which an alternating voltage is applied to produce a discharge and generate ozone gas, and in particular, to an ozonizer which is an essential portion of the flat plate laminate ozone generating apparatus and which includes the high voltage electrodes and low voltage electrodes and to which oxygen is supplied to generate ozone gas.

[0003] 2. Description of the Related Art

[0004]FIG. 27 is a cross sectional drawing of a conventional ozonizer described in, for example, Japanese Patent Publication No. 3113885 “Discharge Cell for Ozone Generator”. In a conventional ozonizer, as shown in FIG. 27, a plurality of low voltage electrodes 7 composed of approximately flat plate-shaped rigid bodies sandwich a pair of block(s) 25 on both sides and are superposed in a thickness direction of the plates to construct a number of electrode module laminated bodies. The electrode module laminated bodies are secured between an electrode presser plate 22 and a base 24 by means of a plurality of fastening bolts 21 passing through both side portions thereof in the laminating direction.

[0005] Each electrode module comprises a pair of upper and lower low voltage electrodes 7, a pair of bilateral blocks 25 sandwiched between the low voltage electrodes 7, 7, dielectric unit(s) 30 disposed between the low voltage electrodes 7, 7 and situated at an inner side of the blocks 25, 25 and a plurality of elastic spacers 26 for forming a plurality of discharge gaps provided for forming discharge gap(s) 6 at both sides of the dielectric unit(s) 30. The elastic spacers 26 constitute rod-shapes of a circular cross-section extending in a direction orthogonal to the page.

[0006] The pair of bilateral blocks 25 is a rigid body of a conductive plate material such as stainless steel plate(s), and, by intervening the blocks between both side portions of the low voltage electrodes 7, a space of an equal gap amount is formed in the thickness direction of the block(s).

[0007] Also, (all of) the drawings are expanded in the vertical direction and an actual thickness is made extremely thin, for example, 3 mm or less in the case of the low voltage electrode 7 and 3 mm or less in the case of the block 25.

[0008] Cooling water passages 9 are formed inside the pair of upper and lower low voltage electrodes 7 and combine as a heat sink. Moreover, a cooling water passage 9 is also formed in blocks 25 of one side. The cooling water passages 9 inside the low voltage electrodes 7 are communicated with a cooling water inlet/outlet 12 provided in the base 24 via the blocks 25 in order to circulate cooling water as a coolant.

[0009] On the other hand, an ozone gas passage 8 is formed in a main surface of the low voltage electrode 7 facing the discharge gap 6 by means of, for example, etching and the like. The ozone gas passage 8 is communicated with an ozone gas outlet 11 provided in the base 24 via an ozone gas passage 8 formed in the blocks 25. Also, an oxygen gas inlet 10 for supplying oxygen gas to the discharge gaps 6 along a direction orthogonal to the page surface is provided at both side portions of discharge gaps 6.

[0010] The dielectric unit(s) 30 disposed in the space surrounded by the upper and low voltage electrodes 7 and the bilateral blocks 25 is a thin sheet shaped rigid body comprising a sandwiched structure of a high voltage electrode 3 sandwiched between a pair of upper and lower glass plates 5. The high voltage electrode 3 is a conductive thin sheet such as a stainless steel sheet and the like and a portion thereof is led outside as a feed terminal (not shown).

[0011] The discharge gap forming elastic spacers 26 provided for forming the discharge gap 6 at both sides of the dielectric unit 30 are thin resin wire rods of a circular cross-section having ozone resistance properties and resiliency, and are disposed in the discharge gaps at a predetermined interval. A thickness of each elastic spacer 26 (outside diameter) is set to be 5-6% larger than each gap amount of the discharge gaps 6 in a non-compressed state.

[0012] With such a setting, the elastic spacer 26 is compressed from above and below by the low voltage electrode 7 and the dielectric unit 30, and the dielectric unit 30 is resiliently pressed from above and below by an equal pressure by this compression and maintained in a central portion, in the vertical direction, of the above mentioned space. Consequently, the discharge gaps 6 of an equal gap amount are formed at both sides of the dielectric unit 30.

[0013] Moreover, in a case where rigid spacers are used instead of the elastic spacers 26, when the blocks 25 are fastened, of course, the rigid spacers used are of a smaller diameter than the elected discharge gap length (the height of the discharge gap in the laminating direction). Thus, the spacers are not compressed in the laminating direction in the discharge gaps.

[0014] Next, operation will be explained.

[0015] When an alternating high voltage is applied between the low voltage electrode 7 and the high voltage electrode 3, a dielectric barrier discharge is generated in the discharge gap 6 via a dielectric 5. Oxygen gas is dissociated to single oxygen atoms by this discharge, and, at roughly the same time, a three body collision is induced between these oxygen atoms, other oxygen molecules and a wall and the like and ozone gas is generated. By using this mechanism and continuously supplying oxygen gas to the discharge gaps 6, the ozone gas generated by the discharge may be continuously derived as ozonized gas from the ozone gas outlet 11.

[0016] An ozone generating efficiency derived from this discharge is normally, at most, 20%. That is to say, 80% of the discharge power heats the electrodes and is lost. Also, the generating efficiency of the ozone gas is dependent on the temperature of the electrode (strictly speaking, the temperature of the discharge gas), and the lower the temperature of the electrode the higher the generating efficiency. Hence, the electrodes are directly cooled with cooling water and the like or a rise in gas temperature in the discharge gaps 6 may be suppressed by shortening the gap length of the discharge gap 6, and the ozone generating efficiency is increased by increasing the electron temperature, ozone decomposition is inhibited and, as a result, an efficient ozonizer capable of deriving highly concentrated ozone gas may be provided.

[0017] In a conventional ozonizer of such a construction, electrode cooling is one sided cooling of the low voltage electrode 7 side and the high voltage electrode 3 is not cooled. Thus, in a case where the same (amount of) power is supplied, the temperature of the gas in the discharge gaps 6 is about four (4) times that of a both side method for cooling the high and low voltage electrodes. Since the amount of generated ozone which is decomposed is increased by this rise in gas temperature, the discharge power density input to the electrode must be further increased and the ozone gas cannot be efficiently generated.

[0018] Moreover, when using the elastic spacers 26, because there are electrons having sufficiently high energy in the discharge gaps 6 due to the discharge, the elastic spacers 26 which are formed of an organic material collide with the high energy electrons (discharge energy) by contact with this discharge and the chemical bond incurs separation damage. When the ozonizer is used in continuous operation, the elastic spacers 26 deteriorate in a short period of time compared to metal spacers and an even flow of gas is made impossible by this deterioration, and there are drawbacks in that efficiency is rapidly reduced and the service life of the apparatus is shortened.

[0019] Also, even in a case where elastic spacers made of an ozone resistant Teflon (registered trademark) are used, the above mentioned high energy electrons (discharge energy) collide and the chemical bond suffers separation damage. Further, even if a material which is generally “flame retardant material” in air is used, as in the case of highly concentrated ozone or oxygen gas atmosphere “combustible material”, there is a problem in that a sublimation reaction of the elastic spacers is activated by the discharge energy at a portion disposed to directly contact the discharge gap and clean ozone cannot be obtained.

[0020] On the other hand, in the case where the rigid spacers are used instead of the elastic spacers 26, they are, naturally, designed to be of a smaller diameter than the elected discharge gap length when being fastened via the blocks 25. Hence, when the discharge gaps 6 are tiny gaps and a high concentration of ozone is to be generated, a pressure loss of the gap partitioned by the spacers 26 for forming the discharge gaps (pressure loss of the tiny gaps between the dielectric 5 and the spacers 26 for forming the discharge gaps) is much smaller than the pressure loss of the discharge gas passages (pressure loss of the gas passages orthogonal to the page surface of FIG. 27). Thus, the even flow of gas is made difficult by the spacers 26 for forming the discharge gaps. Consequently, there are problems in that the ozone generating efficiency is degraded and the ozonizer cannot be made compact.

[0021] Generally, a fluid cannot be evenly flowed unless the pressure loss of the gap formed by the spacer 26 can be made approximately ten (10) times or more the pressure loss of the discharge passage portion. For example, when the discharge gap 6 is 0.1 mm, a gap between the thickness of the spacer 26 and the discharge gap must be highly precise. It is extremely difficult to manufacture the spacers 26 with this sort of precision and dispose them without contacting the discharge gap. For this reason, a large cost increase is incurred in order to manufacture the spacers 26 with good precision and inexpensive manufacture of the apparatus is impossible.

[0022] Moreover, in the conventional ozonizer constructed such as above, the electrode module including the pair of upper and lower low voltage electrodes 7, the bilateral blocks 25 sandwiched between these low voltage electrodes 7, 7, the dielectric units 30 positioned at the inner side of the blocks 25, 25 and disposed between the low voltage electrodes 7, 7, and the plurality of elastic spacers 26 for forming the discharge gap(s) provided at both sides of the dielectric unit 30 for forming the discharge gaps 6 is laminated as a plurality via the low voltage electrodes 7 and is secured between the electrode presser plate 22 provided on top and the base 24 provided at the bottom by the plurality of fastening bolts 21 as a fixing means passing through the electrode module at both side portions thereof in the laminating direction. That is, since the structure is such that the dielectric module held between the low voltage electrodes 7 is fastened at both ends thereof, both sides of the electrode module become fulcrums and the low voltage electrodes 7 which are supposed to be straight are deformed to a circular arc shape, and there is a problem in that, particularly in a discharge gap of 0.1 mm in thickness, the gap length cannot be even and highly concentrated ozone cannot be obtained.

[0023] Further, a conventional ozone passage 8 is manufactured without being gas sealed. Thus, 100% of the oxygen gas raw material cannot be supplied to each electrode module sandwiched by the laminated low voltage electrodes 7. That is, a “short pass phenomena” occurs in which oxygen gas escapes directly to the ozone gas outlet without passing through the discharge passage of the electrode module. When this “short pass phenomena” takes place, the ozone generating efficiency of the electrode module is reduced and highly concentrated ozone cannot be generated; further, since the concentration of the ozone generated by the discharge gap 6 is diluted by a short pass fluid flow of the raw material oxygen gas, there is a problem in that highly concentrated ozone gas cannot be further derived.

SUMMARY OF THE INVENTION

[0024] The present invention was made to overcome all of the above mentioned problems.

[0025] A first object of the present invention is to provide an ozonizer in which an electrode module construction has high reliability without damaging ozone generating characteristics and, nevertheless, the life of the electrode module may be increased.

[0026] A second object of the present invention is to provide an ozonizer in which lamination of an extremely thin sheet-shaped electrode module may be performed by means of a simple operation and further compact modularization may be realized.

[0027] A third object of the present invention is to provide an ozonizer in which a construction of both a high voltage electrode 3 and a low voltage electrode 7 is capable of being cooled well.

[0028] A fourth object of the present invention is to provide an ozonizer in which a purity of generated ozone gas is high, that is, clean ozone gas may be generated.

[0029] According to one aspect of the present invention there is provided an ozonizer including a flat plate-shaped low voltage electrode, a flat plate-shaped high voltage electrode facing a main surface of the low voltage electrode, a flat plate-shaped dielectric and a spacer for forming a discharge gap of a thin thickness in a laminating direction provided between the low voltage electrode and the high voltage electrode. The ozonizer also includes an electrode cooling sheet provided facing a main surface of the high voltage electrode at a side opposite the discharge gap for cooling the high voltage electrode, a thermal conducting/electric insulating sheet sandwiched between the high voltage electrode and the electrode cooling sheet. An alternating voltage is applied between the low voltage electrode and the high voltage electrode and a discharge is produced in the discharge gap injected with oxygen gas to produce ozone gas.

[0030] Thus, the cooling efficiency of the discharge gaps is improved and the temperature of the discharge gaps may be satisfactorily reduced. Accordingly, power density may be increased without decreasing ozone generating efficiency, and size reduction and cost reduction may be provided for an apparatus in which it is possible to reduce the number of electrode modules. Further, since the high voltage electrodes are cooled via the thermal conducting/electric insulating sheets, standard service water may be used as cooling water without using ion exchanged water and the like of small electric conductivity.

[0031] According to another aspect of the present invention there is provided an ozonizer including a flat plate-shaped low voltage electrode, a flat plate-shaped high voltage electrode is provided facing a main surface of the low voltage electrode. The ozonizer also includes a flat plate-shaped dielectric and a spacer for forming a discharge gap of a thin thickness in a laminating direction provided between the low voltage electrode and the high voltage electrode, an electrode cooling sheet provided facing a main surface of the high voltage electrode at a side opposite the discharge gap for cooling the high voltage electrode. The ozonizer also includes a flexible thermal conducting/electric insulating sheet sandwiched between the high voltage electrode and the electrode cooling sheet. An alternating voltage is applied between the low voltage electrode and the high voltage electrode and a discharge is produced in the discharge gap injected with oxygen gas to produce ozone gas.

[0032] Thus, an electric conductivity monitoring device or ion exchanged water circulating equipment and the like is unnecessary and, by reducing the number of apparatus components, it is possible provide for cost reductions or reduce maintenance costs.

[0033] According to still another aspect of the present invention there is provided an ozonizer including a flat plate-shaped low voltage electrode, a flat plate-shaped high voltage electrode provided facing both main surfaces of the low voltage electrode. The ozonizer also includes a flat plate-shaped dielectric and a spacer for forming a discharge gap of a thin thickness in a laminating direction provided between the low voltage electrode and the high voltage electrode, an electrode cooling sheet provided facing a main surface of the high voltage electrode at a side opposite the discharge gap for cooling the high voltage electrode. The ozonizer also includes a thermal conducting/electric insulating sheet sandwiched between the high voltage electrode and the electrode cooling sheet. The ozonizer also includes a manifold block provided between the low voltage electrode and the electrode cooling sheet, and formed with a cooling water passage connected with cooling water passages provided in the low voltage electrode and the electrode cooling sheet, or formed with an ozone gas passage connected with the ozone gas passage provided in the low voltage electrode, both main surfaces of the low voltage electrode facing the discharge gap are covered in an inorganic dielectric film. The ozonizer also inclides a main surface of the dielectric facing the high voltage electrode coated with a conductive film having conductive properties, and the conductive film contacts the high voltage electrode, a flexible thermal conducting sheet is sandwiched between the high voltage electrode and the thermal conducting/electric insulating sheet and the thermal conducting/electric insulating sheet and the electrode cooling sheet, contacting each respectively. An alternating voltage is applied between the low voltage electrode and the high voltage electrode and a discharge is produced in the discharge gap injected with oxygen gas to produce ozone gas.

[0034] Thus, it is possible to form discharge gaps for generating clean ozone in which metallic contamination does not develop and the cooling efficiency of the discharge gaps 6 may be improved.

BRIEF DESCRIPTION OF THE DRAWINGS

[0035]FIG. 1 is a typical explanatory drawing for explaining the ozonizer of the present invention;

[0036]FIG. 2 is a typical detailed cross sectional drawing of an ozonizer electrode of an ozonizer of an Embodiment 1 of the present invention;

[0037]FIG. 3 is a top view of a low voltage electrode of an ozonizer of an Embodiment 2 of the present invention;

[0038]FIG. 4 is cross sectional perspective view taken along the line A-A in FIG. 3;

[0039]FIG. 5 is cross sectional perspective view taken along the line B-B in FIG. 3;

[0040]FIG. 6 is a top view of an electrode cooling sheet of an ozonizer of an Embodiment 3 of the present invention;

[0041]FIG. 7 is cross sectional perspective view taken along the line C-C in FIG. 6;

[0042]FIG. 8 is cross sectional perspective view taken along the line D-D in FIG. 6;

[0043]FIG. 9 is a detailed cross sectional drawing of an ozonizer electrode of an ozonizer of an Embodiment 5 of the present invention;

[0044]FIG. 10 is a top view of a low voltage electrode of an ozonizer of an Embodiment 6 of the present invention;

[0045]FIG. 11 is cross sectional perspective view taken along the line E-E in FIG. 10;

[0046]FIG. 12 is cross sectional perspective view taken along the line F-F in FIG. 10;

[0047]FIG. 13 is a top view of a low voltage electrode of an ozonizer of an Embodiment 7 of the present invention;

[0048]FIG. 14 is cross sectional perspective view taken along the line G-G in FIG. 13;

[0049]FIG. 15 is cross sectional perspective view taken along the line H-H in FIG. 13;

[0050]FIG. 16 is a detailed cross sectional drawing of an ozonizer electrode of an ozonizer of an Embodiment 8 of the present invention;

[0051]FIG. 17 is a side elevation of a high voltage electrode and a dielectric of an ozonizer of an Embodiment 9 of the present invention;

[0052]FIG. 18 is a drawing of a dielectric, as viewed from the top and as viewed from the side, of ozonizer of an Embodiment 10 of the present invention;

[0053]FIG. 19 is a side elevation of a high voltage electrode 3 and a dielectric 5 of an ozonizer of an Embodiment 11 of the present invention;

[0054]FIG. 20 is a detailed cross sectional drawing of an ozonizer electrode of an ozonizer of an Embodiment 13 of the present invention;

[0055]FIG. 21 is a drawing of a thermal conducting sheet, as viewed from the top and as viewed from the side, of ozonizer of an Embodiment 14 of the present invention;

[0056]FIG. 22 is a detailed cross sectional drawing of an ozonizer electrode of an ozonizer of an Embodiment 15 of the present invention;

[0057]FIG. 23 is a cross sectional drawing of a manifold block of an ozonizer of an Embodiment 16 of the present invention;

[0058]FIG. 24 is a top view of a low voltage electrode of an ozonizer of an Embodiment 17 of the present invention;

[0059]FIG. 25 is cross sectional perspective view taken along the line I-I in FIG. 24;

[0060]FIG. 26 is a detailed cross sectional drawing of an ozonizer electrode of an ozonizer of an Embodiment 18 of the present invention;

[0061]FIG. 27 is a cross sectional drawing of a conventional ozonizer;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0062] The present invention will be explained below with reference to the drawings.

[0063]FIG. 1 is a typical explanatory drawing for explaining a flat plate laminated ozone generating apparatus. The flat plate laminated ozone generating apparatus comprises an ozonizer 100 as an essential construction for generating ozone, an ozone transformer 200 for supplying power to the ozonizer 100 and a high frequency inverter 300.

[0064] The high frequency inverter 300 changes to a required frequency power input from a power source input 404 and outputs it to an inverter output cable 403. The ozone transformer 200 increases this power to a predetermined voltage and supplies it as power necessary for generating ozone to the ozonizer 100. The high frequency inverter 300 further has the function of regulating current/voltage and controls a supplied power injection rate.

[0065] High voltage supplied from the ozone transformer 200 is supplied to high voltage electrodes 3 of the ozonizer from a high voltage cable 401 through a high voltage bushing 120. On the other hand, low voltage is supplied to a low voltage electrode 7 from a low voltage cable 402 via a base 24.

[0066] The ozonizer 100 includes a plurality of electrode modules 102 comprising high voltage electrodes 3 and a low voltage electrode 7. A predetermined number of electrode modules 102 are laminated on the base 24 in a direction of an arrow Z in the drawing to construct an ozonizer electrode 101. The ozonizer electrode 101 is covered by a generator cover 110. An ozonizer oxygen gas inlet 130 for supplying oxygen gas including trace amounts of nitrogen and carbon dioxide is provided at the generator cover 110. The supplied oxygen gas impregnates the generator cover 110 and is entrapped in later-described discharge gaps. Meanwhile, an ozone gas outlet 11 for expelling ozone gas formed by the after-described discharge gaps to outside from the ozonizer 100 and a cooling water inlet/outlet 12 for bringing in and putting out cooling water for cooling the electrode modules 102 are provided in the base 24.

[0067] In the flat plate laminated ozone generating apparatus constructed such as above, the present invention particularly relates to the ozonizer 100 which is an essential portion of the ozone generating apparatus, and specifically, to a construction of a an ozonizer electrode 101 and an electrode module 102 of the ozonizer 100.

EMBODIMENT 1

[0068]FIG. 2 is a typical detailed cross sectional drawing of an ozonizer electrode of an ozonizer of Embodiment 1 of the present invention. In FIG. 2, an ozonizer electrode 101 comprises a flat plate-shaped low voltage electrode 7, a flat plate-shaped high voltage electrode 3 facing a main surface of the low voltage electrode 7, a flat plate-shaped dielectric 5 and a spacer (not shown) for forming a discharge gap 6 of a thin thickness in a laminating direction provided between the low voltage electrode 7 and the high voltage electrode 3.

[0069] The ozonizer electrode 101 further comprises an electrode cooling sheet 1 provided facing a main surface of the high voltage electrode 3 at a side opposite the discharge gap 6 for cooling the high voltage electrode 3, and a thermal conducting/electric insulating sheet 2 sandwiched between the high voltage electrode 3 and the electrode cooling sheet 1.

[0070] In the ozonizer electrode 101, an alternating voltage is applied between the low voltage electrode 7 and the high voltage electrode 3 and a discharge is produced in the discharge gap 6 injected with oxygen gas to produce ozone gas.

[0071] Power is supplied to a feed terminal 4 of the high voltage electrode 3 from an ozone transformer 200 (shown in FIG. 2) via a high voltage bushing 120. The high voltage electrode 3 is made of a metal such as stainless steel, aluminum and the like. A main surface of the dielectric 5 is adhered to the high voltage electrode 3. The dielectric 5 is made of a material such as ceramic, glass, silicon and the like. A discharge gap 6 is formed between the dielectric 5 and low voltage electrode 7 by means of a later-described spacer. In the present embodiment, the discharge gap 6 is formed in a disk shape and oxygen gas impregnated in the generator cover 110 of FIG. 1 is injected from an entire periphery of the discharge gap 6 toward a central direction.

[0072] Oxygen gas flowing in the discharge gap 6 is converted to ozone by applying an alternating voltage between the low voltage electrode 7 and the high voltage electrode 3. The ozone gas converted to ozonified oxygen by the discharge gap 6 is led to the ozone gas outlet 11 from a central portion of the low voltage electrode 7 via an ozone gas passage 8 provided in the low voltage electrode 7.

[0073] The low voltage electrode 7 is a thin sheet-shaped conductive rigid body comprising two (2) conductive plates, such as stainless steel plates and the like, joined so as to form the ozone gas passage 8 there-between. A cooling water passage 9 for increasing an ozone generating efficiency is provided in the low voltage electrode 7 in addition to the ozone gas passage(s) 8. A gas temperature in the discharge gap 6 is lowered by flowing cooling water in the cooling water passage 9.

[0074] The high voltage electrode 3 is disposed at a main surface of the low voltage electrode 7 at a side opposite the discharge gap 6 via the thermal conducting/electric insulating sheet 2. Thus, the low voltage electrode 7 cools the high voltage electrode 3 in addition to the discharge gap 6. Also, a water cooling type electrode cooling sheet 1 is disposed at an uppermost high voltage electrode 3 via the thermal conducting/electric insulating sheet 2. The electrode cooling sheet 1 is a thin sheet-shaped rigid body comprising two (2) steel plates, such as stainless steel plates and the like, joined so as to form a cooling water passage 9 there-between. That is, the cooling water passage 9 is also formed in the electrode cooling sheet 1 and cooling water flows in this cooling water passage 9.

[0075] The ozone gas passage 8 formed in the low voltage electrode 7 is connected to the ozone gas outlet 11 provided in the base 24 via an ozone gas passage 8 formed in a manifold block 23. On the other hand, the cooling water passages 9 formed in the electrode cooling sheet 1 and low voltage electrode 7 are connected to the cooling water inlet/outlet 12 provided in the base 24 via a cooling water passage 9 formed in the manifold block 23.

[0076] Although not specifically shown in the drawings, a gasket material, such as an O-ring and the like, is sandwiched between the electrode cooling sheet 1 or low voltage electrode 7 and manifold block 23 or base 24 for water-tightness of the cooling water. Moreover, a gasket material, such as an O-ring and the like, is also sandwiched for air-tightness of the ozone gas.

[0077] An electrode module(s) 102 comprising the low voltage electrode 7, high voltage electrode 3, dielectric 5, spacer, electrode cooling sheet 1 and thermal conducting/electric insulating sheet 2 is fastened and fixed between an electrode presser plate 22 and the base 24 by fastening bolts 21 passing through each structural element. The discharge gaps 6 are maintained at a predetermined thickness in the laminating direction by means of the manifold block 23.

[0078] Moreover, in the present embodiment, the dielectric 5, necessary for silent (dielectric barrier) discharge, is provided between the low voltage electrode 7 and high voltage electrode 3 and the spacer is disposed between this dielectric 5 and the low voltage electrode 7 to provide the discharge gap 6. However, the spacer may also be disposed between the high voltage electrode 3 and the dielectric 5 to provide the discharge gap 6.

[0079] Next, operation will be explained, when an alternating voltage is applied between the low voltage electrode 7 and the high voltage electrode 3 a silent (dielectric barrier) discharge is produced by the discharge gap 6. When oxygen gas is passed in the discharge gap 6, the oxygen is converted and ozone is produced. The oxygen gas impregnating the generator cover 110 passes through the discharge gap 6 formed between the low voltage electrode 7 and dielectric 5 and in this course is converted to ozone. In the present embodiment, the high voltage electrode 3, dielectric 5 and discharge gap 6 formed there-between are each formed in a an approximate disk shape. The oxygen gas flows from an entire periphery of the dielectric 5 toward a center and becomes ozonified oxygen gas in the discharge gaps 6.

[0080] In order to efficiently create ozone it is necessary that the discharge gap 6, which is a space of particularly thin thickness, be precisely maintained. The electrode module laminated body is fastened between the electrode presser plate 22 and the base 24 by means of the plurality of fastening bolts 21 disposed in the blocks 23 and passing through both side portions thereof in the laminating direction so as to obtain a predetermined gap precision. The discharge gap(s) 6 is formed by means of discharge gap spacers (not shown) disposed at a surface of the low voltage electrode 7. 

1. (Amended) An ozonizer comprising: a flat plate-shaped low voltage electrode; a flat plate-shaped high voltage electrode facing a main surface of said low voltage electrode; a flat plate-shaped dielectric and a spacer forming a discharge gap having a thickness in a laminating direction, located between said low voltage electrode and said high voltage electrode; an electrode cooling sheet facing a main surface of said high voltage electrode at a side opposite said discharge gap for cooling said high voltage electrode; and a thermally conducting and electrically insulating sheet sandwiched between said high voltage electrode and said electrode cooling sheet, wherein, when an alternating voltage is applied between said low voltage electrode and said high voltage electrode and a discharge is produced in said discharge gap and when oxygen is injected into said gap, ozone is produced.
 2. (Amended) The ozonizer according to claim 1 including at least two flat metal plates including grooves and adhered together with the grooves aligned to form an ozone gas passage and a cooling water passage inside said low voltage electrode.
 3. (Amended) The ozonizer according to claim 1 including at least two flat metal plates including grooves and adhered together with the grooves aligned to form a cooling water passage in said electrode cooling sheet.
 4. (Amended) The ozonizer according to claim 2, wherein said flat metal plates are adhered together by heat and pressure only.
 5. (Amended) The ozonizer according to claim 1 including an inorganic dielectric film covering both main surfaces of said low voltage electrode facing said discharge gap.
 6. (Amended) The ozonizer according to claim 5, wherein said dielectric film is a ceramic material.
 7. (Amended) The ozonizer according to claim 5, wherein said dielectric film is a glass material.
 8. (Amended) The ozonizer according to claim 1 including a conductive film coating a main surface of said dielectric facing said high voltage electrode, wherein said conductive film contacts said high voltage electrode.
 9. (Amended) The ozonizer according to claim 1 including a conductive adhesive adhering said dielectric and said high voltage electrode together.
 10. (Amended) The ozonizer according to claim 8 including an inorganic insulating film coating a peripheral edge portion of said conductive film.
 11. (Amended) The ozonizer according to claim 9 including an inorganic insulating film coating a peripheral edge portion of said conductive film. 12 (Amended) The ozonizer according to claim 1, wherein said high voltage electrode has an outside diameter smaller than an outside diameter of said dielectric.
 13. (Amended) The ozonizer according to claim 8, wherein said high voltage electrode has a diameter smaller than an outside diameter of said conductive film covering said dielectric.
 14. (Amended) The ozonizer according to claim 1 including a flexible thermally conducting sheet sandwiched between said high voltage electrode and said thermally conducting and electrically insulating sheet and said thermally conducting and electrically insulating sheet and said electrode cooling sheet, contacting each of said high voltage electrode, said thermally conducting and electrically insulating sheet, and said electrode cooling sheet, respectively.
 15. (Amended) An ozonizer comprising: a flat plate-shaped low voltage electrode; a flat plate-shaped high voltage electrode facing a main surface of said low voltage electrode; a flat plate-shaped dielectric and a spacer forming a discharge gap having a thickness in a laminating direction, located between said low voltage electrode and said high voltage electrode; an electrode cooling sheet facing a main surface of said high voltage electrode at a side opposite said discharge gap for cooling said high voltage electrode; and a flexible thermally conducting and electrically insulating sheet sandwiched between said high voltage electrode and said electrode cooling sheet, wherein, when an alternating voltage is applied between said low voltage electrode and said high voltage electrode, a discharge is produced in said discharge gap and when oxygen is injected into said discharge gap, ozone is produced.
 16. (Amended) The ozonizer according to claim 1 comprising a manifold block located between said low voltage electrode and said electrode cooling sheet, and including a cooling water passage connected with cooling water passages in said low voltage electrode and said electrode cooling sheet, respectively, or including an ozone gas passage connected with an ozone gas passage in said low voltage electrode.
 17. (Amended) The ozonizer according to claim 16, wherein said manifold block has an elastic structure with an elastic function in the laminating direction of said low voltage electrode and said high voltage electrode.
 18. (Amended) The ozonizer according to claim 2, wherein said spacer is disposed at a position facing a rib forming a cooling water passage of said low voltage electrode.
 19. (Amended) An ozonizer comprising: a flat plate-shaped low voltage electrode; a flat plate-shaped high voltage electrode facing a main surface of said low voltage electrode; a flat plate-shaped dielectric and a spacer forming a discharge gap having a thickness in a laminating direction, located between said low voltage electrode and said high voltage electrode; an electrode cooling sheet facing a main surface of said high voltage electrode at a side opposite said discharge gap for cooling said high voltage electrode; a thermally conducting and electrically insulating sheet sandwiched between said high voltage electrode and said electrode cooling sheet; a manifold block located between said low voltage electrode and said electrode cooling sheet, and including a cooling water passage connected with cooling water passages in said low voltage electrode and said electrode cooling sheet, or including an ozone gas passage connected with an ozone gas passage in said low voltage electrode; an inorganic dielectric film covering main surfaces of said low voltage electrode facing said discharge gap; a conductive film coating a main surface of said dielectric facing said high voltage electrode, wherein said conductive film contacts said high voltage electrode; and a flexible thermally conducting sheet sandwiched between said high voltage electrode and said thermally conducting and electrically insulating sheet and said thermally conducting and electrically insulating sheet and said electrode cooling sheet, contacting each of said high voltage electrode, and thermally conducting and electrically insulating sheet, and said electrode cooling sheet, respectively, wherein, when an alternating voltage is applied between said low voltage electrode and said high voltage electrode, a discharge is produced in said discharge gap, and when oxygen is supplied to said discharge gap, ozone is produced.
 20. (Amended) The ozonizer according to claim 1 comprising a plurality of electrode modules, each module comprising said low voltage electrode, said high voltage electrode, said dielectric, said spacer, said electrode cooling sheet, and said thermally conducting and electrically insulating sheet, laminated. 